Novel materials as oxygen carriers for energy applications

作者：Evdou A; Zaspalis V; Nalbandian L^*

来源：Bulgarian Chemical Communications, 2013, 45: 211-218.

• Hydrogen
• Perovskites
• Chemical-looping reforming
• Dense membrane reactor

Perovskites have the ability to accommodate large concentrations of vacancies in their structure and to reversibly pick up and deliver oxygen at high temperatures, thus they are ideal candidates for use as oxygen carrier materials. The performance of perovskites with the general formula La1-xMexMyFe1-yO3 (Me = Sr, Ca, M = Ni, Co, Cr, Cu) as both oxygen carriers for syngas generation from methane in the Chemical Looping Reforming (CLR) concept and as dense membrane materials in the Dense Membrane Reactor (DMR) concept is explored in the present work. Oxygen is withdrawn from the crystal lattice of the perovskites by oxidation of a fuel. Water, oxygen or carbon dioxide, are then added to the solid which provide the necessary oxygen atoms to fill-in the lattice vacancies. The performance of the mixed perovskitic materials doped with 5% M in the B-site (M=Ni, Co, Cr or Cu), is compared. Also, substitution of Sr with Ca in the A-site of the perovslcite is explored. Dense, disc shaped membranes of the materials were utilized in a membrane reactor. Experiments at 1000 degrees C revealed the possibility of performing the reduction and oxidation steps simultaneously and isothermally on each side of the membrane reactor. The system is able to operate on partial pressure based desorption without the need of a carbon containing reductant, so that a process towards hydrogen production, based only on renewable hydrogen source such as water, can be established.

• 出版日期2013